1. Field of the Invention
The present invention relates generally to optical devices, and more particularly to an optical interconnect that can be configured to add and subtract optical signals.
2. Description of the Art
The telecommunications industry is rapidly switching from electronic systems to hybrid platforms which utilize both electronics and photonics to increase the operational bandwidth. Today""s electronic communication systems consist of electrical networks, microwave amplifiers, microwave transmitters, and high speed semiconductor receivers. There are numerous electrical devices available so this architecture works well in the confines of electronics. There are problems in moving to hybrid platforms, however, because few electro-optical devices are available to convert electrical signals into optical signals. Moreover, eventually as optical systems come into use, purely optical signal processing devices will be required.
What is needed, therefore, are more optical interconnects especially one that is capable of adding and subtracting optical signals directly, without conversion between electronic and optical architectures.
The present invention involves an optical interconnect that utilizes an optical transcription material, while maintaining a fast temporal response, and thus a high bandwidth. This device is applicable for phase modulated, amplitude modulated and polarized optical signals and responds to a separate signal beam and a probe beam.
The optical transcription material (OTM) which will be described subsequently in more detail, utilizes a linear or nonlinear optical pump-probe mechanism to relay the arithmetic information from the signal beam to the probe beam. The signal beam, also referred to as the pump beam, induces a time dependent index of refraction change, which is interrogated by a probe beam, also referred to as the reading beam. Through this mechanism, information which is encoded onto the signal beam is transcribed into polarization rotation, amplitude modulation or phase modulation of the probe beam. The optical interconnect speed is limited by the intrinsic response time of the OTM.
Briefly, the present invention comprises an optical interconnect, that can be configured for adding or subtracting two or more optical signals. The optical signals contain information which is amplitude, polarization or phase encoded. A probe laser generates an optical probe beam. The optical device includes an OTM that responds to the optical signals and the probe beam such that a characteristic of the probe beam is changed. A signal processor or detector senses the changed characteristic and develops an output optical signal representative of the summed or subtracted information contained in the input optical signals.
In other aspects, the present invention subtracts polarization multiplexed signal and reference beams and employs a time compensation architecture.
The foregoing and additional features and advantages of this invention will become apparent from the detailed description and accompanying drawing figures below. In the figures and the written description, numerals indicate the various elements of the invention, like numerals referring to like elements throughout both the drawing figures and the written description.